Demand for unmanned security systems is increasing. This is because, if an alarm system is established by installing sensors in a surveillance region and is used, the number of managers necessary for security can be reduced and also the number of times managers encounter a dangerous situation can be minimized.
A related-art alarm system just monitors events occurring in sensors. That is, the related-art alarm system just monitors in which sensor an event (for example, an intrusion) has occurred. Accordingly, it is impossible to determine a more detailed current situation through the related-art alarm system.
In addition, monitoring by the related-art alarm system includes fragmentary operations. That is, when events occur in various sensors in sequence, the events are treated separately and collected information are fragmentarily used. Therefore, there is a problem that information may not be efficiently used.